stewart



R. T. STEWART.

FUEL SUPPLY SYSTEM Fon INTERNAL coMBusTloN ENGINES.

APPLICATION FILED MAY 29, IJIG.

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KQMMMQU m TV. STEWART. FUEL SUPPLY SYSTEM FOR INTERNAL COMBUSTION ENGINES. APPLICATION FILED MAY 29. lvlf4 1,313,925. Patented A116'. 26, 1919.

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R. TI STEWART. FUEL SUPPLY SYSTEM EUR INTERNAL coMBusTloN ENGINES.

APPLICATION FILED MAYZQ. 916. 1,3 1 3, 925 Patented Aug. 26, 1919.

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REID T. STEWART, OF PITTSBURGH, PENNSYLVANIA.

romsmizrssrnm ron INTERNAL-consumen ENGINES.

Spe'c'ict'ioii ot Letters Patent.

Patented Aug. '26, 1919.

` Gontinuatlon in part of application Serial No. 72,384, iiled January 17, 1916. This application tiled lay 29,

1910. Serial No. 100,436.

' 'citizen vof the ing one form of Toallwhvmmay concern:

Be it known that I, REID Tf. STEWART, a A United v States,v residing 'at Pittsbur h, in the county. 'cf'Alleg'heny 'and State of, ennsylvania, have invented a new and useful Improvement in Fuel-Supply Systems for Internal-Combustion Engines,

.fof which the followin is Ia full, clear, an'

exact description, re eren'cebe'inghad to the accompanying drawings, forming part of this lspecification,- in w ich- Fig. 8 is a sectional elevation illustrating n s'ill another form of my invention.V

. fold.

. My invention has relation tofuel supply systems for 4internal combustion engines, and more particularly to a system of this character which is designed for use when the main source of. fuel supply is either permanently or temporarily located at a lower level than the carbureter, and in which the suction of the engine isutilized to cause a flow of the fuel from themain source o1v supply to the carbureter. l n

One object of my invention isto rovide a system of this character which s all be simple and efficient in its construction and mode of operation under varying service conditions.

Another object is to `provide a vacuum fuel feed system, in which the vacuum is continuous in its action and in which the vacuum range may be made less to any desired extent than that in the engine mani- A further object is to provide a fuel feed system of this 'character which shall have no atmospheric vents at any point between the main fuel supply tank and the engine intake.

A further. object of the invention is to provide means whereby be operated practically continuously with a small degree of vacuum, with open throttle,

I f and therefore, with high volumetricA engineefficiency, thereby" giving the maximum site peints and the fuel feed maystill further 'object is to `rovide aparati'is 'of this kind, in whih t e parts are ew and 'simple' in character and can be readily assembled and which are readily accessible f o`r renewalf'or re airs.

lefler'ringl first to that orm of my invention'shown in Fig. 1, the numeral 1 desig nates a lsupplemental tank which is supplied with liquid fuel bv means of an unrestricted passage 2, connectin its upper portion with a main f'uel supp y tank 3. A partial vacuum is maintained in the supplemental tank by means of a restricted passage 4, which connects its upper portion with the described. 'The Boat chamber 5, communicates by means of a passage 6 with the car- `bureting chamber 7 wherein partial vacuum exists. In the form shown in this figure, I have shown the pipe or tube forming the passage 4 as extending upwardly through the supplemental tank, w ich is shown as supported directly upon the float chamber. 8 designates another fuel feed passage leading from the bottom of the su plemental tank' into the upper portion o the'iioat chamber. The passa esi 4 and 8 are controlled, respectively, y valves 10v and v12, whose stems 11 and 13 rest upon the top of a float 14, preferably at diametrically oppoequidistant from the4 axis through the center of flotation. The weight of the valve 10 and its stein 11 is made greater than that of the valve 12 and its stem 13,'

(or the left side of the float may be over weighted in any Iother suitable manner) thereby giving a tendency to the float to list toward the side which carries the heavier load, yand in order that .the'valve' 10 may always open before the valve 12. The float is preferably mounted on a verticaly tapered pin 15, the float having a central opening engaging Seid pin in e manner to permit fthe free vertical mbv'ement'1 .ofthe linut., oombined with a limited osclllatlng or tlpplng movement. The extent of the actual Vtipping movement of the oat, dueto the excess Weight'on the' sideof the valve 10, is preferably limited by the amount of taper to be given to the pin 1 5, o r it may be tothe walls of the opening 16.' 4This taper is made sufficient to -eausethe valve 12 to open them stant that suficientfuel ceases to .enter past the 'valve 10.

The passagewhich connects the top of the supplemental tank 1 with the upper portion 15 of the loatchamber, acts as amain fuel feed passage, as a suction or vacuum passage, and also as an air 1fuel vapor vent. This passage, controlled in the .manner described, functions to maintain 'a store of fuel in the supplemental tank up to the level shown in Fig. 1, whenever the Vacuum produced by the engine issuiiicient to lift the fuel to.

the top of the supplementaltank. Any condition which causes an interruptionl of ber 7 is controlled by a valve 17. This.

valve isA held to its sea't 19 primarily by means of the spring 29, and eecondarily by meansof av pistoni 21, attached thereto and slidably. mounted" within the cylinder 22,

causes the ccnstruotionand arrangement makes it pos- Whichis supported within or adjacent to the air 'inlet 18. The upper end ofthe cylinder 22 is closed, and the space within communi.-. Oates by lmeans of a passage 28 with the carbureter outlet24 on the engine-side of the throttle valve 25. When thethrottle valve is wide open, as indicated in the dotted po; sition 25e, the vacuum .r in cylinder 22l is substantially equal to that in the carbureting chamber 7, and for this condition the pres sure of valve 1.7 against its seat is. dueto the action of the spring 29 alone. When, how-A ever, the throttlevalve is partially closed,

'as indicated in full lines in Fig. 1, the degree of vacuum is greater inthe cylinder 22 than it is in the cal-bursting `chamber 7 This piden 21 to exert an upward pull on. the air valve' 171 vThis upward pull, whlchl is substantially zero with a wide open throttle may be increased to `any desired extent -or partially closed throttle, by suitablyenlargng'the diameter of the piston' 21, with respect to' the, air valve 17. This sible to operate acontinuous vacuum fuel feed system` on al small degree of vacuum with open throttle, and therefore, Withhigh volumetric engine ecency. This condition passage 4 resumes its gives maximum power' a( .times when power is most demanded, while atthe seme time,

with the throttle partially closed, sufficient vacuum may be had for lifting the fuel to the top of the supplemental tank.

The air valve 17 and its seat 19 are prefer-iA ably given such shapeas to form an annular Venturi passage for the inflow of air to the carburetingy chamber 7. The fuel inlet 26 is preferably located `et 'fliethroat of this venturi The fuel is preferably drawn up through the hollow `valve stem 27, and is distributed to the 28, formed Within the air valve itself and leading to the outlet' 26. This outlet 26 preferably consists of anal-row slot extendmgaround the peri hery of the' valve, the latter being form shown, to provide for 'this slot, which is periphery of the valve 17 by means of the passage or passages in two sections, as"

located at `the point ofcontact of the valve with said seat. I prefer to give the disl tributingv passage 28 and th'efuel outlet shown for the purpose of causing the fuel to issue more or less in the direction taken by the air while passing through the throat ofthe venturi. By thus adding an induction action to the .venturi action, I obtain. a more effective flow of fuel from the float chamber to the .carbureting chamber. By the combined action of the air valve 1.7,. the fuel outlet 26, the vacuum piston 2]., the passage 23, and the throttle. 2 5, I am enabled to produce a perfect admixture off the fuel with the -air when suchcondition is desired viz.. when operating" under partially closed yopening 26 the' inclined' or conical form etv throttle especially when using liquid fuelsv which vaporize with difliculty.

The lower end of the hollow valve stem has secured thereto a piston 29, working in the liquid dash pot 29, which may be supplied from the float chamber by means of openings 29 in the pieton. The purpose o this dash pot is to prevent any tendency of the valve 1 to vibrate or flutter. The pis- Y ton 29-has a dependinghollow hub o1" sleeve which telescopes over a metering pin 30`,`and which terminates in the annular seat 32. This pin is of gradually reduced `diameter toward its lower end, its upper end being.

made of such size as to below through the `seat 32;.and said pinis of sufficient weight to seat firmly .upon an adjusting screw 35. The Weighted lower end 31' has therein a cone-shaped cavity 33,

easily enter' from which engages the conical point 34 of the adjusting screw 35. Thisconstruction rovides in a simple manner for the longitu inal adjustment of tho'meterng pin and also a'perfeet means of lateral self-adjuetinent of the' pin to. its surrounding vseat 32. The oonstruction and arran ement valso permits of the parts being readily assembled and easilv accessible for any purpose. TheI y lower section 29'of the dash pot 29al is made y removable for this purpose.

. the may operate sired lead of penn In the form of my lnvention shown in Fig. 2, the parts are generally constructed and arranged substantlally as in'Fig. 1, and corresponding parts have been given the samey reference numerals with the letter a affixed thereto. In this form, however, in-

stead of a single float 14, controlling the two valves, separate floats 36 and 37 are ein- .ployed. The float 37 is set at a higher level than the float 36,

so that the valve 10a will open sooner than the valve 12a. By im'- mersing the float 37 to a less degree than the float 36, the valve 10` may lbe given any deover the valve 12, In this figure, I havea so shown the carbureter as having an anterior throttle valve A, and

'a posterior throttle valve B, the two throttles having an adjustable connection C, by which in unison. v.

the form shown in Fig. 3, I employ a single float 38, and the proper lead i's given to the valve controlling the primary feed lpassage 4", by immersing one end of the float this more deeply irndeeper than the other,

and its mersed end actuating the valve 12",

other end actuating the stem 11" of the main A feed valve. In this case, the stem 11" is pivotally connected to the float.

In Fi'g. 4, the same result is obtained by seating the valve stem 13c upon a spring 39 'of the single float 40, upon which the valve stem 11 rests. In this construction, the valve 12 will first seat, but the spring 39 will yield to the further upward movement of the iioat until the'other valve is closed.

In Fig. 5, I show still another way of accomplishing the same result by the use of a divided float having the superimposed sections 41 and 42. The upper part 41 controls the stem 11d of the main valve, whilethe lower part 42 carries and controls the supplementalY valve 12". As long as the fuel -in the ioat chamber does not rlse above a certain level, the two float'parts act as a unit,

but as the depth of the fuel increases and the valve 12" closes, the upper iioat member will continue to rise and close the Vother valve.

Another way of accomplishing thesame result is shown in Fig. 6, in which the single float 43 acts at one side of the center of the lever arm 44, the valve 11 being carried ori the longer arm of this lever and the valve 12 on the shorter arm thereof.

Still another arrangement for the same purpose is shown in Fig. 7, in which a single oat 45 of ball form is employed, the stem 13 of the valve 12t being` pivoted to one side of the float, and the stem 11' of the valve 10t being pivoted to the opposite side of the float. `Valve 10'l having its stem 11 heavier than the valve 12', and its stem 13', the result is a tendency to tip the float so as to first close the valve 12'.

- rangement This tipping tendency is limited by the n this figure, I have also shown an arof the air inlet valve for the same purpose as that shown in Fig. 1, but somewhat diierently applied. 47 designates the air inlet, 48 the controlling valve therefor, 49 the piston connected to the stem of said valve and working in the cylinder 50, whose upper end is connected by a passage 51' with the outlet passage 52, leading to the engine. The passage 51 communicates with the passage* 52 at the engine side ofthe throttle valve 53. The 'action'of the piston 49 and cylinder 50 is similar to that of the iston 21 and cylinder 22, first described. T e top of V the float chamber 5t is connected by means of passa e 6", shown in dotted lines, to the space a jacent to the inlet controlled b valve 48. The construction shown in Fig. is, however, Aone which can be `readily a plied to various forms of carbureters. n this figure, the pipe 2" from the main storage tank connects with the ipe 4t in which the valve stem 11l is locate with a branch connection 54 leading into the supplemental tank. In this arrangement, the main feed is directly from the main storage tank, surplus fuel 'passing through 54 into the supplemental tank.

In Fig. 8, I have shown still another em' bodiment of my invention, generall vsimi-l lar to that,shown -in Fig. 1, but invo ving a number of modifications. Parts `of `this figure which correspond to similar parts in F1 1 are given the same reference numerals wit the letter g afxed. ,It will be noted that in Fig. 8, the valve 17.5 is reversed with respect to the valve 17 of Fi .'1, and is arranged to'seat downwardly y gravity instead of upwardly by the action of a spring. The action ofthe piston 21 is reversed also, the suction passage 235 communicating with the cylinder 228, below the said this figure, the feed passage for t e fuel instead of being within the stem of the valve, as in Fig. 1, is formed by a separate passage l 56 in the wall of the carbureter, and communicates with an annular passage 57 below the seat for the valve. 178,' and communicates with the seating surfaceby an annular discharge slot 58. They fuel is thus ,discharged at a similar point, to that of Fig. 1, but -independently of the valve. The

`metering pin 30g is carried by the dash pot and adjustment thereof is obthe stem 27S y of the so i.

iston. In

`raising or lowering the piston and corresppndingly `adjusting the metering pin.

.In this figure I have also shown a modl- Hed arrangement ofthe Heat 14g, in whlch the *centering pin 15 of Fig. `1 is omitted and substantlally the same result is obtained by making the Heat ef downwardly tapered er fruste-cenical form. The side of the Heat upon which' the valve stem v11g rests is overweighted with respect te Athe opposite side either by the increased weight `of said stem er in any other suitable manner.

It will be readily understood that the double valve arrangement herein shown and described effectively provides for the proper supply of fuel to the Heat chamber under all conditions. Se long as the vacuum action produced by the engine is sufficient to maintain the supplemental tank Hlled to about the level shown, the supply te `the Heat chamber is past the main valve. When, for any reason, the level of fuel in the supplemental tank falls, the supplemental valve then opens andthe fuel stored in such tank is utilized. y

The main valve automatipally prevents fuel-Hoeding under any operating condition. At the saine time, the main valve automatically provides, when required, free communication betyveen the upper portions of the supplemental tank and the Heat chamber for the purpose of venting and of transfer of suction.

It will be noted from Fig. 7 that the sup.

plementaltank Yneed net be supported `directly upon the Heat chamber, but that it i combustion` englnes,

' lplemental .tank

may be placed in any convenient relation thereto and lthat the connections between this tank and the Heat chamber may be varieulsy arranged.

y` invention is susceptible of various other modifications within the spirit and scope rof the appended claims.

Thepresent application is, inpart, a centinuatien of my copending appllcation, Serial No. 72,384, filed January 17, 1916.

' 1. In a fuel supplyusystem for internal a main supply tank, a supplemental tank,

plemental tank, Heat means in the Heat c amber, a valve actuated by said Heat and controlling the supplemental fuel supply from the supplemental tank, there being suction passages Iconnecting the upper portion of the Hoat'chamber with the upper portion of the 'supplemental tank and with the carbureting chamber ofthe carbureter,

said Asuction the main fuel supply passage from the supvalve controlling the mainfuel supply passage and controlled by saidHoat means, substantlally 'as described.-

` acarbureter having a n Heat chamber supplied from :the su passages also forming te the Heat chamber, andv a fnaiaeae 2. Ina fuel supply `system for internal combustion engines, a main supply tank, a

supplemental tank, a carbureter having a` Heat chamber supplied `from the supplemental tank, Heat means in the Heat chamber, a valve actuated by said Heat means and controlling the supplemental fuel t supply from the supplemental tank, there being suctien passages connectingthe upper portion of the Heat chamber with the upper portion of the supplemental tank and with the carbureting chamber of the; carbureter, ene of' said suction. passages also forming the main fuel supply passage from the supplementalv .c

tank to the Heat chamber, and a valve centrolling the main fuel supply passage and,

controlled by said Heat means, said last f named valve having means for giving it a lead of opening over the supplemental'fuel` control valve, substantially, as described.

3. A carbureter havingl afloat chamber, f Heat means in said Heat chamber, a storage chamber, a feed cennectien'leading from the lower portion of the storage chamber inte the Heat chamber, another feedV connection leading from the upper pertionef the sterage chamber into the Heat chamber, a valve controlled by said Heat means for eachl of said connections, and means whereby the v valve for thelast named vconnection may be given a lead of openingl over the valve for the first named connection, substantially as described.

l4. In a fuel supply system for internal combustion engines, a main `supply tank, a

per portion of the supplemental tank and with the carbureting chamber of the earbuneter, one of said suction passagesalso forming the the supplemental tank te the'Hoat chamber, and another valve controlling the main fuel supply, said last named valve having means forglving it a lead of opening over the `supplemental fuel tially asdescribed. l t

5. In -a fuel supply system for internal combustion engines, a supplemental tank, means operated by `th control valve, ,substanlv vith fuel, another chamber at a lower level 'than the supplemental tank, afuel supply passage, leading from the upper portlen of the supplemental 1 tank -inte the last named chambe r, another fuel supply `passage leading from the lower ertien' ofthe supeplemental tank into the ast named cham r, a valve for each of asi.

leu

supplemental tank having a su ply cennecmain fuel supply passage from engme for supplying the supplemental tank said connections, and means for giving one of said valves a lead of action over the other a' fuel stora e tank, of a chamber located at Vgiv1ng`one of over the other a lower leve than said tank and havin two feed passages -connecting it with di erent levels of said tank, a separate valve controlling each of said dpassages, and means for sai substantially as described. 7. In a fue supply system for internal combustion engines', the combination of a fuel storage tank, a.

at a lower level than said tank and havin valves a lead of action float chamber located Q two feed assages connecting it with dif? s of said tank, a separate valve controlling each of said passages, and a tiping iioat for 'actuating said valves, sald float actin to ve one valve a lead of action over e o er, together with means for tipping the float, substantially as described.

8. In a fuel suppl lsystem for internal combustion engines, e combination with a fuel storage tank, of a float chamber located at a lower level than said tank and havintg two feed passages connecting it with di ferent levels of said tank, a separate valve controlling each of said apassagea'and means for giving one of said v ferent leve over the other, said means comprising a tipping float which supports the valves, and one of said valves bein weighted in excess of the other, substantia y as described. y

A9. In a fuel suppl y system for internal combustion engines, t e combination with a mam fuel storage tank, of a supplemental fuel storage tank, a chamber having a feed ves a 1ead of action connection with said supplemental stora evtank, and a suction passage leading from t e engine to` the main storage tank and communicatmg with, the supplemental storage tank above the level of -fuel therein, said passage communicating with said chamber and also formin a fuel supply connection for said cham r, substantially as described. v

10. In a fuel supply system for internal combustion engines, the combinationwith a main fuel storgge tank, of a supplemental fuel storage ta a chamber having a feed connection with said supplemental storage tank, and a suction passage leading from 'age tank,

' combustion engines,

the engine -to the main storage tank and communicating with the supplemental Stor age tank,y said passage communicating with said chamber and also forming a fuel supply connection for said cham er, together with separate valves controlling the two fuel supplies for said chamber, and means for giving one of said valves a lead `of action over the other one, substantially as described.

11. In a. fuel supply combustion engines, a chamber,

a supplemental storage tank, the action of the engine is caused to raise the fuelfrom the main storage tank, the float chamber having two separate fuel feed connections, separate valves for controlling said connections, and means operated by the level of' the fuel in said system for internal means whereby givin one of said valves a lead of action over e other, substantiallyas described.'

12. In a fuel suppl system for internal e combination with a fuel storage tank, of a iloat ebamberlocated at a lower level than said tank and having two feed passages connecting it with different levels of said tank', a separate valve' controlling each of said passages, and means for givin one of said. valves a over t e other, said means comprislng atip'- ping float which supports the valves, one

side of the float being weighted in excess of the other, substantially as described.

13. In combination, a carbureter having a fuel feeding nozzle, a chamber feeding said nozzle, a supplemental chamber feedipg said first-named chamber, a storage ta feeding said supplementalV` hamber said supplemental chamber normall'y'hol in a reserve supply of fuel and feedmgsaid t named chamber b said reserve supp by the level of fuel in said rst named cham- ;ber for drawing on said reserve suppl when the main su ply fails to maintain t e fuel level in sai first named chamber between predetermined limits. v

In testimony whereof, I have hereunto set m hand. y REID T. s'r-EWART. Witnesses:

W. C. Lyon, H. M. Conwnr.

lead of action ychamber for controlling said valves and for means of an excess over- 4 y, and means controlled 

